The introduction of pars plana vitrectomy about 40 years ago heralded a new age in posterior segment surgery. The development of this technique in a closed system, which prevents a drop in eye pressure during surgery, made it possible for the first time to master operations on the vitreous body, retina, and macula. Since then, there have been ongoing developments in surgical techniques and instrumentation, always with two objectives in mind: to shorten surgery time and eye recovery time. This has primarily been achieved by creating smaller and more efficient instruments for incisions of less than one millimeter that cause less surgical trauma. Also, microscopes are now on the market that offer improved visualization and illumination of the surgical site.
Vitrectomy with only two incisions
Three separate incisions are normally made in the pars plana for vitreoretinal surgery. This part of the eye between the outer edge of the retina and the ciliary body contains neither large vessels nor functionally irreplaceable tissue. One of the incisions is used for the infusion that keeps eye pressure stable. The illuminator is inserted through the second incision. The third incision is made for the surgical tools, e.g., vitrectome, microscissors, microforceps. Having several channels offers two key advantages: several minor sclerotomies are less traumatizing than one large one, and instruments can be changed without any major fluctuations in pressure. Dr. Luca Cappuccini, Director of Ophthalmology at Reggio Emilia Hospital in Italy, experienced eye surgeon and specialist in vitreoretinal surgery, uses a variation of this technique that only requires one channel for infusion and one for instruments. This means he has both hands free for working with surgical instruments. The reason he can eliminate the channel for the endoilluminator is the high-end optics and the unique illumination concept of the Leica M844 F40 surgical microscope.
Dr. Cappuccini, how did the idea of the bi-manual technique for vitreoretinal surgery originate?
When we put the new Leica M844 F40 into operation and I tried out the microscope together with Carlo Spizuoco, Leica Application Manager, we were immediately impressed by the outstanding optics and illumination technology. We saw that the Leica M844 F40 provided a good view of the ocular fundus without using an endoilluminator. That gave us the idea of doing without the incision for the illuminator altogether during surgery. After a few trials, we found that it worked – very well, in fact. Not having to control the endoilluminator with one hand means that I now have both hands free for surgical instruments. The key technical prerequisite for doing without the light channel and therefore using the two-handed surgical method is the illumination concept of the Leica M844 F40. The direct halogen illumination in conjunction with the integrated OttoFlexTM II auxiliary light delivers sharply defined and highly contrasted images of the retina and ensures excellent light conditions in the entire surgical site, including the periphery. Within the main visual field I can vary the diameter of the OttoFlexTM II illumination field in a sterile fashion from 4 to 35 millimeters to get extra light exactly where I need it.
Using the Leica M844 F40, I have substantially improved the way I perform demanding surgery on the back of the eye. It’s not only easier for me as a surgeon to do the complex operation successfully, the patient benefits as well. This microscope is a successful example of what doctors and users expect of industrial partners like Leica Microsystems: ongoing further development of imaging technology and practical handling combined with optimal applicational flexibility.
What are the benefits of your surgical technique for your patients and for you as a surgeon?
Having both hands free for doing the surgery, I can handle the instruments more easily and therefore operate more quickly. Shorter operations mean that we save time. But the benefits for patients are much more important. Having two sclerotomies instead of three incisions in the sclera accelerates eye recovery and causes fewer postoperative problems. Reducing the number of incisions also reduces the risk of sepsis during surgery.
For what indications is the bi-manual technique a particular advantage?
The technique is especially useful for treating proliferative membrane growth, macular holes, and diabetic macular edema. I have also had excellent experience using this technique for retinopathy of prematurity (ROP), where there is a proliferation of abnormal vessels in the retina. A mild version of ROP is relatively common, although the severe form is extremely rare. However, babies born before the 32nd week of pregnancy, babies with a birth weight below 1,500 grams or babies requiring artificial respiration for longer than three days are particularly at risk. Severe stages can lead to scarring, myopia or blindness due to retina detachment.
Particularly for severe cases of ROP with retina detachment, in which laser coagulation is not sufficient, the two-handed technique was helpful for dissecting the retina quickly and without any incidents. When we operate on preterm babies, we naturally try to keep the duration of the surgery as short as possible to minimize the strain on the not yet fully developed organ. This is where the benefits of the new technique for added patient safety are particularly apparent.
Do surgeons need extra training for this technique?
Any operation on the retina demands a lot of experience and a delicate touch, and the handling of the OttoFlexTM II requires particular practice. It is important to develop a feeling for the light conditions at different diameters of the auxiliary illumination to ultimately achieve an optimal image of the retina. A good exercise for confident mastery of the Leica M844 F40’s illumination technology is the use of vitrectomy lenses. This additional lens is placed on the cornea if necessary to provide a panoramic view of the ocular fundus during surgery. This exercise can be done before starting a cataract operation, for example.
Has your new technique caused a stir amongst your colleagues?
My colleagues have already heard about my new way of operating. Many ophthalmologists approach me and want to know more about it. I am naturally very pleased that other specialists have heard about my technique. I’m coming in contact with new people interested in it all the time, and we often invite ophthalmologists to watch my operations and discuss the technique with me in detail.
Leica M844 F40 with OttoFlex™ and APO OptiChrome™
The premium class Leica M844 F40 with its exclusive direct illumination system offers the best clarity, contrast, and color at safer low-light levels for the patient, and provides fatigue-free viewing for the surgeon. With two bulbs and two prisms, the Leica M844 creates true three-dimensional illumination. Using a focused, direct illumination system instead of fiber optics, the Leica M844 takes a ray of light and projects a crisp, sharp, and homogeneous image even at very low light levels.
OttoFlex™ II, an integrated independent illumination system, gives a brilliant red reflex even in low light conditions and enhances the view’s contrast. Difficult anatomical conditions are more easily visualized by this unique system. Continuously adjustable from 4 mm to 35 mm diameter,
OttoFlexTM II puts the brightness where the surgeon needs it most.
The Leica APO OptiChrome™ provides an extraordinary degree of light transmission for maximum detail recognition, which is critical for all types of ophthalmic microsurgery. For the limited available light in posterior segment surgery, a high degree of light transmission is essential. For refractive and anterior segment surgery, low light is always better for the patient.